Picture coding device, picture coding method, and picture coding program, picture decoding device, picture decoding method, and picture decoding program

A picture coding device includes a coding information storage unit configured to initialize to fill a history-based motion vector predictor candidate list with history-based candidates having at least predetermined motion vector and reference index, a motion vector predictor candidate derivation unit configured to derive a history-based candidate included in the history-based motion vector predictor candidate list as a motion vector predictor, a motion vector subtraction unit configured to calculate a motion vector difference by subtracting the derived motion vector predictor from a motion vector by which inter prediction is performed, wherein the coding information storage unit adds the motion vector to the history-based motion vector predictor candidate list as a history-based candidate and updates the history-based motion vector predictor candidate list.